Drooping too early... and maybe also a P (Phosphorus) deficiency?

[elcoloan]

Hello!
Not that my plant is really sick or that i' really concerned, but I come again with 2 inquiries concerning my Mephisto's "24 carat x 3 bears og": 1. Why is she drooping so early (3 hours before lights out)?, and 2. Does she have a P def and if so how should i address it if i'm still on time to do so?

Background info:
She turned 44 days old yesterday. She showedfirst psitils at around day 21-22. and started forming buds at about day 37-38. She is in an 2.2 gal autopot in mostly coco, getting 1.2 EC nutes (MCv1 500-515 ppm, tap water 70 ppm, 30 epsom) with pH between 6.0-6.3 mostly close to 6.0-6.1, but past few days i lowered pH to 5.8 to help with P absortion.

She's under a quantum board style light in 18/6 schedule, and according to my PAR meter (sq-520) she is currently getting 450 ppfd at the tallest top, 330 at lowest top... so a DLi between 20 and 30. I had been adjusting light height and photoperiod duration to get DLI above 20 ( i had always used less than 20 in this tent and during the first month or so of life of this current plant), but DLI has not been above 40 and chose to settle below 30 but above 20 for the flowring of this plant. I have the dark period set during the day to help with the cold temps during the night... o lights go out at 11 am and turn back on at 5 pm.

RH is 52-76% during lights on but mostly between 55-65%, and temps are 21-26C / 70-78F at cannopy level... mostly around 25C / 78F during lights on.

She had been very drooppy most of the time and i think it was due to low RH (below 50%)... so i increased RH to be always above 50% a couple weeks ago and it kinda worked.

Problems/Inquiries:

1. I say "kinda worked" because she looks very perky during most of lights on time, but i'm noticing that she always droops again 3 hours before lights out. I had noticed my plants droop about an hour before lights out, but 3 hours before, even 2, seems too much. Thinking it was too much light i reduced the DLI to 20-30 (adjusting height of light, changing photoperiod, etc), but this was happening even before when DLI was below 20. So guess i can rule out drooping because too much light.
Why would you say she is drooping so early (up to 3 hours before lights out)? Maybe it doesn't like it's roots so wet as the Autopot works? Does this make any sense?

2. I started noticing about a week or so ago (once she began flowering) that many leaves were getting reddish stems, lower leaves were yellowing and then getting some light brown blotches or stains on those same yellowing leaves (the brown spots are from the early Ca def symptoms), so that day i increased MC from 470 ppm to 500-515 ppm . Many stems started and continued turning reddish and the green of most of the leaves turning into a blueish shade. Since she is full on flowering and MC is low in P i assume it's a P def. I already tried lowering pH. Also, when i tried giving 33 ppms of Bud Explosion last week, i got Ca def very quickly so i stopped that... assume it was because of the high K in the version i have of BE (I have the old 0-20-40 version).
So, I wonder if i'm correct and i should try again to add some bloom supplement high in P (i have MKP 0-54-33) to the next reservoir change or if it's too late for that... and i was thinking if doing so if i'd add just 30 ppms of it. Or should i just increase the MC's EC? Any input on this regard?

Any how, I apologize for the wordy post as always. Here are some pics to balance things out and give a better reference for what i'm saying:

Day 43 (pics with out LED light, with camera flash):



Day 44 (yesterday, a couple hours after lights on):


Day 45 (today, about 3 hours before lights off):


Any input is appreciated.

 

[Proph]

Couple of questions.. Why are you adding Epsom salt? Is MC v1 actually low in potassium??

When I use auto pots, I only use 1 gallon of water at a time in the res until I have a good read on the plants..That way I can correct any issues that arise before they get out of hand.

The drooping before light come on is normal. It's called circadian rhythm..

The discoloration on the leaves looks a lot like either a potassium or magnesium issue, or both.
A sign of deficiency DOES NOT automatically mean ADD MORE.. I cant stress that enough.. It does not mean add more! It means "find the problem".. Almost every MC grow I've seen runs into this same issue at the start of flower. Im not yet convinced that the MC feed ratio is formulated for cannabis. The ratios seems to be really high and cause lock outs when used as directed. Lock outs happen when there is too much of one nutrient in the medium.. Too much of one nutrient, can lock out (make unavailable for use) one or more other nutrients.. Here's a chart for reference..

As you can see, magnesium and potassium are directly related. Too much mag, locks out P.. Too much P, locks out mag.. That's why I asked why are you adding epsom salt (which a source of magnesium).. I'm also basing this off of the location of the issue.. Most "mobile nutrient" issues start at the bottom of the plant.. That's because the plant is pulling nutrients from those leaves and moving it other places where it's needed more. Both potassium and magnesium are mobile nutrients.. Here's a chart for reference...

It's hard to say how to correct this issue.. Very few people has been able to "dial in" mega crop. The ratios are all over the map. Adding more or increasing the feed dosage is definitely NOT the answer though. I would empty my res and put a gallon of plain ph'd water in it and let that get completely used up. Then start back with super light feeds.

 

[elcoloan]

Couple of questions.. Why are you adding Epsom salt? Is MC v1 actually low in potassium??

When I use auto pots, I only use 1 gallon of water at a time in the res until I have a good read on the plants..That way I can correct any issues that arise before they get out of hand.

The drooping before light come on is normal. It's called circadian rhythm..

The discoloration on the leaves looks a lot like either a potassium or magnesium issue, or both.
A sign of deficiency DOES NOT automatically mean ADD MORE.. I cant stress that enough.. It does not mean add more! It means "find the problem".. Almost every MC grow I've seen runs into this same issue at the start of flower. Im not yet convinced that the MC feed ratio is formulated for cannabis. The ratios seems to be really high and cause lock outs when used as directed. Lock outs happen when there is too much of one nutrient in the medium.. Too much of one nutrient, can lock out (make unavailable for use) one or more other nutrients.. Here's a chart for reference..
View attachment 1245419

As you can see, magnesium and potassium are directly related. Too much mag, locks out P.. Too much P, locks out mag.. That's why I asked why are you adding epsom salt (which a source of magnesium).. I'm also basing this off of the location of the issue.. Most "mobile nutrient" issues start at the bottom of the plant.. That's because the plant is pulling nutrients from those leaves and moving it other places where it's needed more. Both potassium and magnesium are mobile nutrients.. Here's a chart for reference...View attachment 1245423

It's hard to say how to correct this issue.. Very few people has been able to "dial in" mega crop. The ratios are all over the map. Adding more or increasing the feed dosage is definitely NOT the answer though. I would empty my res and put a gallon of plain ph'd water in it and let that get completely used up. Then start back with super light feeds.

Thanks for replying.

Well I knew the droopiness was normal but didn't realize it could start so early. I was used to 1 hour before lights out... 3 seems alot.

Hmm... and i think you are using the symbol P incorrectly or misunderstanding me (my fault for wrting so many words)... MC is said to be low in P (phorphorus) and very High in K (Potasium) and N (nitrogen). And I'm actually using it a little below what is directed. I add Mg (Epsom) because all my previous runs in the same conditions I got Mg def which didn't look at all like this yellowing that I thought is more because of N def (I was running low EC of MC for the stage)... then the brown blotches appeared and also the reddish stems. I was thinking of adding the MKP for the P, not for the K. Precisely by adding Bud Explosion which is high in K is when i got Ca def and I just added 1/5 of the directed BE dose. Believe me... I've tried to bee very careful and follow your advice and not just increase nutes.

And i also just prepare a galon of nutes each time. Last one is almost done.

 

[Proph]

Thanks for replying.

Well I knew the droopiness was normal but didn't realize it could start so early. I was used to 1 hour before lights out... 3 seems alot.

Hmm... and i think you are using the symbol P incorrectly or misunderstanding me (my fault for wrting so many words)... MC is said to be low in P (phorphorus) and very High in K (Potasium) and N (nitrogen). And I'm actually using it a little below what is directed. I add Mg (Epsom) because all my previous runs in the same conditions I got Mg def which didn't look at all like this yellowing that I thought is more because of N def (I was running low EC of MC for the stage)... then the brown blotches appeared and also the reddish stems. I was thinking of adding the MKP for the P, not for the K. Precisely by adding Bud Explosion which is high in K is when i got Ca def and I just added 1/5 of the directed BE dose. Believe me... I've tried to bee very careful and follow your advice and not just increase nutes.

And i also just prepare a galon of nutes each time. Last one is almost done.

I don't think it's your fault.. MC v1 has a ratio of 9-6-16.. 6 is not low for P.. I honestly think these ratios are not intended for cannabis. And yes that was my mistake.. I was the P.. But the plant doesn't look like p def issue.. I was looking at the symptoms more than your words. The symptoms aren't similar to phosphorus def. I've never had a good answer for mega crop issues... @Mañ'O'Green seems to have mega crop figured out.. All I can really say is that when I use the MC calculator on their site, the dosage that the calculator recommends is a lot lower than what the bag says. Maybe MañO' can help out

 

[elcoloan]

I don't think it's your fault.. MC v1 has a ratio of 9-6-16.. 6 is not low for P.. I honestly think these ratios are not intended for cannabis. And yes that was my mistake.. I was the P.. But the plant doesn't look like p def issue.. I was looking at the symptoms more than your words. The symptoms aren't similar to phosphorus def. I've never had a good answer for mega crop issues... @Mañ'O'Green seems to have mega crop figured out.. All I can really say is that when I use the MC calculator on their site, the dosage that the calculator recommends is a lot lower than what the bag says. Maybe MañO' can help out

OK, it's just that i have expereinced how just MCv1 during flower makes very leafy buds, so i wanted to see if i could avoid it by using some bloom supplements hearing that some extra P in early flower is good.
But I think i will stay with just the MC for now then. Mañ'O'Green had already told me to take away the Epsoms (for other reasons) but i've been stuborn.

 

[Mañ'O'Green]

GreenLeaf is selling version 3 (the fourth iteration) of Mega Crop and it runs better than previous versions. It is not perfect and I do not think there is a perfect one part for cannabis (except true living organics). I am running The GreenLeaf 2 Part Mega Crop and I have that pretty well dialed in for Photoperiod plants. My next grow with it will be Autos.

In your case I think two things may be going on, a little too much magnesium and relative humidity may be a little too high for the maturity stage the plant is in. The magnesium is locking out the calcium but this is very minor. The drooping leaves happen when the plant is growing rapidly and the humidity gets high shutting down the stomata. This strands the water in the leaves making them heavy.

I think go with MC at 400 PPM and add 50 PPM Cal-mag and 30 PPM of BE. These are the numbers that worked for me in the past.

Get your DLI up to 38 if you can. Really strong light strength can cause tacoing not drooping.

 

[elcoloan]

GreenLeaf is selling version 3 (the fourth iteration) of Mega Crop and it runs better than previous versions. It is not perfect and I do not think there is a perfect one part for cannabis (except true living organics). I am running The GreenLeaf 2 Part Mega Crop and I have that pretty well dialed in for Photoperiod plants. My next grow with it will be Autos.

In your case I think two things may be going on, a little too much magnesium and relative humidity may be a little too high for the maturity stage the plant is in. The magnesium is locking out the calcium but this is very minor. The drooping leaves happen when the plant is growing rapidly and the humidity gets high shutting down the stomata. This strands the water in the leaves making them heavy.

I think go with MC at 400 PPM and add 50 PPM Cal-mag and 30 PPM of BE. These are the numbers that worked for me in the past.

Get your DLI up to 38 if you can. Really strong light strength can cause tacoing not drooping.

OK, will get that DLI up to 38,

And will do next reservoir refill as you say... so total 1.1 EC / 550 ppm (400 MC1, 50 CMP, 30 BE, 70 tap)....
And just to be clear on the BE... i have BE that i bought like 2 years ago, so it's the 0-20-40 version, not the latest 0-33-37 + Magnesium nor the one before this one which was 0-26-37... no problem there?

 

[elcoloan]

In case anyone is interested... i'd like to report that after lowering the RH the early drooping stopped but the plant keeps growing and filling up... so yeah... now she barely droops and it begins 1 hour before lights out so thanks for the input everyone... hope this all is somehow useful for others.